1#
2# syslog.pl
3#
4# $Log:	syslog.pl,v $
5#
6# tom christiansen <tchrist@convex.com>
7# modified to use sockets by Larry Wall <lwall@jpl-devvax.jpl.nasa.gov>
8# NOTE: openlog now takes three arguments, just like openlog(3)
9#
10# call syslog() with a string priority and a list of printf() args
11# like syslog(3)
12#
13#  usage: require 'syslog.pl';
14#
15#  then (put these all in a script to test function)
16#
17#
18#	do openlog($program,'cons,pid','user');
19#	do syslog('info','this is another test');
20#	do syslog('mail|warning','this is a better test: %d', time);
21#	do closelog();
22#
23#	do syslog('debug','this is the last test');
24#	do openlog("$program $$",'ndelay','user');
25#	do syslog('notice','fooprogram: this is really done');
26#
27#	$! = 55;
28#	do syslog('info','problem was %m'); # %m == $! in syslog(3)
29
30package syslog;
31
32use warnings::register;
33
34$host = 'localhost' unless $host;	# set $syslog'host to change
35
36if ($] >= 5 && warnings::enabled()) {
37    warnings::warn("You should 'use Sys::Syslog' instead; continuing");
38}
39
40require 'syslog.ph';
41
42 eval 'use Socket; 1' 			||
43     eval { require "socket.ph" } 	||
44     require "sys/socket.ph";
45
46$maskpri = &LOG_UPTO(&LOG_DEBUG);
47
48sub main'openlog {
49    ($ident, $logopt, $facility) = @_;  # package vars
50    $lo_pid = $logopt =~ /\bpid\b/;
51    $lo_ndelay = $logopt =~ /\bndelay\b/;
52    $lo_cons = $logopt =~ /\bcons\b/;
53    $lo_nowait = $logopt =~ /\bnowait\b/;
54    &connect if $lo_ndelay;
55}
56
57sub main'closelog {
58    $facility = $ident = '';
59    &disconnect;
60}
61
62sub main'setlogmask {
63    local($oldmask) = $maskpri;
64    $maskpri = shift;
65    $oldmask;
66}
67
68sub main'syslog {
69    local($priority) = shift;
70    local($mask) = shift;
71    local($message, $whoami);
72    local(@words, $num, $numpri, $numfac, $sum);
73    local($facility) = $facility;	# may need to change temporarily.
74
75    die "syslog: expected both priority and mask" unless $mask && $priority;
76
77    @words = split(/\W+/, $priority, 2);# Allow "level" or "level|facility".
78    undef $numpri;
79    undef $numfac;
80    foreach (@words) {
81	$num = &xlate($_);		# Translate word to number.
82	if (/^kern$/ || $num < 0) {
83	    die "syslog: invalid level/facility: $_\n";
84	}
85	elsif ($num <= &LOG_PRIMASK) {
86	    die "syslog: too many levels given: $_\n" if defined($numpri);
87	    $numpri = $num;
88	    return 0 unless &LOG_MASK($numpri) & $maskpri;
89	}
90	else {
91	    die "syslog: too many facilities given: $_\n" if defined($numfac);
92	    $facility = $_;
93	    $numfac = $num;
94	}
95    }
96
97    die "syslog: level must be given\n" unless defined($numpri);
98
99    if (!defined($numfac)) {	# Facility not specified in this call.
100	$facility = 'user' unless $facility;
101	$numfac = &xlate($facility);
102    }
103
104    &connect unless $connected;
105
106    $whoami = $ident;
107
108    if (!$ident && $mask =~ /^(\S.*):\s?(.*)/) {
109	$whoami = $1;
110	$mask = $2;
111    }
112
113    unless ($whoami) {
114	($whoami = getlogin) ||
115	    ($whoami = getpwuid($<)) ||
116		($whoami = 'syslog');
117    }
118
119    $whoami .= "[$$]" if $lo_pid;
120
121    $mask =~ s/%m/$!/g;
122    $mask .= "\n" unless $mask =~ /\n$/;
123    $message = sprintf ($mask, @_);
124
125    $sum = $numpri + $numfac;
126    unless (send(SYSLOG,"<$sum>$whoami: $message",0)) {
127	if ($lo_cons) {
128	    if ($pid = fork) {
129		unless ($lo_nowait) {
130		    do {$died = wait;} until $died == $pid || $died < 0;
131		}
132	    }
133	    else {
134		open(CONS,">/dev/console");
135		print CONS "<$facility.$priority>$whoami: $message\r";
136		exit if defined $pid;		# if fork failed, we're parent
137		close CONS;
138	    }
139	}
140    }
141}
142
143sub xlate {
144    local($name) = @_;
145    $name = uc $name;
146    $name = "LOG_$name" unless $name =~ /^LOG_/;
147    $name = "syslog'$name";
148    defined &$name ? &$name : -1;
149}
150
151sub connect {
152    $pat = 'S n C4 x8';
153
154    $af_unix = &AF_UNIX;
155    $af_inet = &AF_INET;
156
157    $stream = &SOCK_STREAM;
158    $datagram = &SOCK_DGRAM;
159
160    ($name,$aliases,$proto) = getprotobyname('udp');
161    $udp = $proto;
162
163    ($name,$aliases,$port,$proto) = getservbyname('syslog','udp');
164    $syslog = $port;
165
166    if (chop($myname = `hostname`)) {
167	($name,$aliases,$addrtype,$length,@addrs) = gethostbyname($myname);
168	die "Can't lookup $myname\n" unless $name;
169	@bytes = unpack("C4",$addrs[0]);
170    }
171    else {
172	@bytes = (0,0,0,0);
173    }
174    $this = pack($pat, $af_inet, 0, @bytes);
175
176    if ($host =~ /^\d+\./) {
177	@bytes = split(/\./,$host);
178    }
179    else {
180	($name,$aliases,$addrtype,$length,@addrs) = gethostbyname($host);
181	die "Can't lookup $host\n" unless $name;
182	@bytes = unpack("C4",$addrs[0]);
183    }
184    $that = pack($pat,$af_inet,$syslog,@bytes);
185
186    socket(SYSLOG,$af_inet,$datagram,$udp) || die "socket: $!\n";
187    bind(SYSLOG,$this) || die "bind: $!\n";
188    connect(SYSLOG,$that) || die "connect: $!\n";
189
190    local($old) = select(SYSLOG); $| = 1; select($old);
191    $connected = 1;
192}
193
194sub disconnect {
195    close SYSLOG;
196    $connected = 0;
197}
198
1991;
200